Traditionally, it is not possible to modify any data stored on the ROM. But. Note that some ROM chips have rewrite abilities, so data can easily be erased from them. As you read on, you will learn more.
ROM is the most important type of electronic storage device, which comes in-built to the device during manufacturing. Some of the devices that have ROM Chips include computers, game consoles, Mobile Phones, car radios, Printers, flash drives and other storage devices, Digital Watches, embedded devices, Microcontrollers etc. ROM chips generally are installed directly to the board of a device. ROM also is a non-volatile memory which means it retains its information even when power is removed from the device it was installed on.
This is in contrast to RAM. ROM is a solid-state memory that will only read data stored in it. When this data gets stored, it will not be changed or deleted.
Information about the Manufacturer such as the Manufacturer’s Logo etc. is as example of the Information that can be stored on the ROM.
DIFFERENT TYPES OF ROM
1. MROM (Masked Read Only Memory): This was the first ROM which comes [in-built] with all the pre-programmed data set and instructions. These types of ROMs are called masked ROMs because they cannot be erased or modified after manufacture
2. PROM (Programmable ROM): this type of ROM can easily be modified only once by the user. They [The users] can buy a blank PROM (just like buying an empty non rewritable CD) & enters desired contents by using a PROM program.
3. EPROM (Erasable & Programmable ROM): This type of ROM can easily be erased just by exposing it to an ultra-violet light (Those type of Light used in the bank to check for fake currencies) for around 40 minutes. Generally, an EPROM eraser attains this function. You may reprogram it as per the similar process as the PROM just with an EPROM program.
4. EEPROM (Electrically Erasable & Programmable ROM): this type of ROM is an update to the EPROM. It can be programmed, reprogrammed & erased electrically for around ten thousand times. The process of Erasing & programming takes only about 4 – 10 milliseconds.
One drawback of EEPROMs is that EEPROM can only erase/reprogram only 1 byte of data at a particular time.
5. FLASH ROM: this is an advanced EEPROM version. One primary benefit of using FLASH ROM is that you may delete and write blocks of the data over 512 bytes at one time. While, in EEPROM, you will delete or write just 1-byte of data at a particular time. Also FLASH ROM is much faster than the EEPROM, it can be reprogrammed without even removing it from your computing device, its access time is a bit high, over 45 – 90 nanoseconds and It’s highly durable because it can bear high temperature & intense pressure.
Written by: destiny idika
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Published 3 Years Ago On Wednesday, April 21, 2021
Updated 3 Years Ago On Friday, November 12, 2021
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